Field of the Invention
The present invention relates to an orbital plane control of a spacecraft and more specifically to a spacecraft and an orbital plane change method therefor for changing the orbital plane of a rotating orbit around the earth to another orbital plane different in the orbital inclination or in the right ascension of the ascending node.
Background Art
Changing the orbit of a satellite is referred to as “orbit control (correction).” An orbit control method is able to be mainly classified into in-plane control and orbital plane control.
The term “in-plane control” means changing the size and shape of the orbit by firing engines for acceleration or deceleration within the orbital plane of the satellite.
The term “orbital plane control” means changing an angle of the orbital plane to the equator (the angle is referred to as “orbital inclination”) or an angle formed by a point at which the orbit intersects the equatorial plane in a direction from the south to north latitude (the point is referred to as “ascending node”) and the reference axis (the angle is referred to as “right ascension of the ascending node”).
The orbital plane control is disclosed, for example, in Non-Patent Document 1.
Moreover, a general “orbit change” is disclosed in Patent Documents 1 and 2. In addition, Patent Document 3 discloses “a method of controlling the longitude of the reference point in an inclined elliptical spaceship orbit.”    [Non-Patent Document 1] “Guidebook for JAXA Space Activities, Mission 4 Artificial satellite,” JAXA Space Education Center, [Searched for on Apr. 22, 2015], Internet <edu.jaxa.jp/materialDB/html/guidebook/guidebook/main.html>    [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-80598    [Patent Document 2] Japanese Patent Application Laid-Open No. Hei 6-286698    [Patent Document 3] Japanese Patent Application Laid-Open No. 2002-46697
In an orbital plane control for changing an orbital plane, conventionally engines are fired in a direction perpendicular to the orbital plane of a satellite. Alternatively, the orbit is swung by perturbation and then a desired orbit is maintained when it is acquired. The term “perturbation” means an orbital variation caused by the gravitational field of the earth. In addition, an orbital swing caused by perturbation is referred to as “drift.”
Fuel is necessary for changing an orbital plane by using engines. In this case, for example, in order to achieve, a useful change in an orbital plane (10° or more), a lot of fuel (a half or more of the self weight) is required. On the other hand, a drift caused by perturbation requires a long period of time (several ten days) to achieve the useful change in the orbit similarly.